Effects of UV-LED Irradiation on <em>E. coli</em> in Water Disinfection

Ultraviolet light-emitting diode (UV-LED) is a newly emerging UV light source with a potential of replacing the conventional chemical methods, mercury UV lamps and xenon lamps in water disinfection applications. In this chapter, we will first give a general description on the status of E. coli disinfection in water by UV-LEDs. Then the main text will concentrate on our experimental studies. We will discuss the effects of single and combined UV-LED irradiation on E. coli in water, including the inactivation efficiency, the recover percentage after the UV-LED irradiation, the optimal wavelength for low energy consumption, differences in pulsed and continuous operations of UV-LEDs, effect of UVA-LED followed by UVC-LED irradiation and vice versa, and finally the effect of TiO2-assisted photocatalytic disinfection

Flexible wearable sensors for crop monitoring: a review

Crops were the main source of human food, which have met the increasingly diversified demand of consumers. Sensors were used to monitor crop phenotypes and environmental information in real time, which will provide a theoretical reference for optimizing crop growth environment, resisting biotic and abiotic stresses, and improve crop yield. Compared with non-contact monitoring methods such as optical imaging and remote sensing, wearable sensing technology had higher time and spatial resolution. However, the existing crop sensors were mainly rigid mechanical structures, which were easy to cause damage to crop organs, and there were still challenges in terms of accuracy and biosafety. Emerging flexible sensors had attracted wide attention in the field of crop phenotype monitoring due to their excellent mechanical properties and biocompatibility. The article introduced the key technologies involved in the preparation of flexible wearable sensors from the aspects of flexible preparation materials and advanced preparation processes. The monitoring function of flexible sensors in crop growth was highlighted, including the monitoring of crop nutrient, physiological, ecological and growth environment information. The monitoring principle, performance together with pros and cons of each sensor were analyzed. Furthermore, the future opportunities and challenges of flexible wearable devices in crop monitoring were discussed in detail from the aspects of new sensing theory, sensing materials, sensing structures, wireless power supply technology and agricultural sensor network, which will provide reference for smart agricultural management system based on crop flexible sensors, and realize efficient management of agricultural production and resources

Intelligent Fusion of Structural and Citation-Based Evidence for Text Classification

This paper investigates how citation-based information and structural content (e.g., title, abstract) can be combined to improve classification of text documents into predefined categories. We evaluate different measures of similarity, five derived from the citation structure of the collection, and three measures derived from the structural content, and determine how they can be fused to improve classification effectiveness. To discover the best fusion framework, we apply Genetic Programming (GP) techniques. Our empirical experiments using documents from the ACM digital library and the ACM classification scheme show that we can discover similarity functions that work better than any evidence in isolation and whose combined performance through a simple majority voting is comparable to that of Support Vector Machine classifiers

High-Efficiency All-Dielectric Metalenses for Mid-Infrared Imaging

Metasurfaces-based flat optics, which can make use of existing foundry planar technology for high-throughput production, allows the arbitrary control of the wavefront and polarization of light within subwavelength thick structures. So far, however, flat optics for the mid-infrared (MIR) has received far less attention than devices operating at visible or near-infrared wavelengths. Here, polarization-insensitive, highly efficient, all-dielectric metalenses operating in the MIR around 4 µm are demonstrated. The metalens is designed using rigorous coupled-wave analysis and is based on hydrogenated amorphous silicon (α-Si:H) nanopillars supported by an MgF2 substrate. The metalenses produce close to a diffraction-limited focal spot and can resolve structures on the wavelength scale where the focusing efficiency reaches 78% at a magnification of 120×. The imaging qualities are comparable with commercial bulk-molded chalcogenide aspheric lenses. These results provide novel solutions for existing MIR technology and nurture new functionalities with the population of miniaturized and planarized optoelectrical devices.The authors acknowledge the facility support from the ANU node of the Australian National Fabrication Facility (ANFF). This work was supported by China Scholarship Council (201506310074); Australian Research Council (ARC) Future Fellowship (FT110100853); and the ARC Centre of Excellence for Ultrahigh Bandwidth Devices for Optical Systems (CE110001018)

Harmonic-Rejection Compact Bandpass Filter Using Defected Ground Structure for GPS Application

A miniaturized bandpass filter (BPF) using defected ground structure (DGS) resonator with the characteristic of harmonic rejection is developed in this paper. The second and third harmonics of the proposed BPF are rejected by the characteristic of stepped-impedance DGS resonator. Moreover, open stubs are established so that two adjustable transmission zeros can independently be created to extend the stopband and improve the rejection level. Finally, a second-order BPF, centered at 1.62 GHz with a stopband extended up to 5.6 GHz and a rejection level better than 20 dB, is designed and implemented for GPS application. A good agreement between simulation and measurement verifies the validity of this design methodology

Population genomics of wild Chinese rhesus macaques reveals a dynamic demographic history and local adaptation, with implications for biomedical research

Background The rhesus macaque (RM, Macaca mulatta) is the most important nonhuman primate model in biomedical research. We present the first genomic survey of wild RMs, sequencing 81 geo-referenced individuals of five subspecies from 17 locations in China, a large fraction of the species’ natural distribution. Results Populations were structured into five genetic lineages on the mainland and Hainan Island, recapitulating current subspecies designations. These subspecies are estimated to have diverged 125.8 to 51.3 thousand years ago, but feature recent gene flow. Consistent with the expectation of a larger body size in colder climates and smaller body size in warmer climates (Bergman's rule), the northernmost RM lineage (M. m. tcheliensis), possessing the largest body size of all Chinese RMs, and the southernmost lineage (M. m. brevicaudus), with the smallest body size of all Chinese RMs, feature positively selected genes responsible for skeletal development. Further, two candidate selected genes (Fbp1, Fbp2) found in M. m. tcheliensis are involved in gluconeogenesis, potentially maintaining stable blood glucose levels during starvation when food resources are scarce in winter. The tropical subspecies M. m. brevicaudus showed positively selected genes related to cardiovascular function and response to temperature stimuli, potentially involved in tropical adaptation. We found 118 single-nucleotide polymorphisms matching human disease-causing variants with 82 being subspecies specific. Conclusions These data provide a resource for selection of RMs in biomedical experiments. The demographic history of Chinese RMs and their history of local adaption offer new insights into their evolution and provide valuable baseline information for biomedical investigation

Enhancing the Spin–Orbit Coupling in Fe3O4 Epitaxial Thin Films by Interface Engineering

10.1021/acsami.6b0947884027353-2735

Towards graphane field emitters.

We report on the improved field emission performance of graphene foam (GF) following transient exposure to hydrogen plasma. The enhanced field emission mechanism associated with hydrogenation has been investigated using Fourier transform infrared spectroscopy, plasma spectrophotometry, Raman spectroscopy, and scanning electron microscopy. The observed enhanced electron emissionhas been attributed to an increase in the areal density of lattice defects and the formation of a partially hydrogenated, graphane-like material. The treated GF emitter demonstrated a much reduced macroscopic turn-on field (2.5 V μm-1), with an increased maximum current density from 0.21 mA cm-2 (pristine) to 8.27 mA cm-2 (treated). The treated GFs vertically orientated protrusions, after plasma etching, effectively increased the local electric field resulting in a 2.2-fold reduction in the turn-on electric field. The observed enhancement is further attributed to hydrogenation and the subsequent formation of a partially hydrogenated structured 2D material, which advantageously shifts the emitter work function. Alongside augmentation of the nominal crystallite size of the graphitic superstructure, surface bound species are believed to play a key role in the enhanced emission. The hydrogen plasma treatment was also noted to increase the emission spatial uniformity, with an approximate four times reduction in the per unit area variation in emission current density. Our findings suggest that plasma treatments, and particularly hydrogen and hydrogen-containing precursors, may provide an efficient, simple, and low cost means of realizing enhanced nanocarbon-based field emission devices via the engineered degradation of the nascent lattice, and adjustment of the surface work function.For assistance in ATR FTIR and EDXRF measurements we thank Dr Bob Keighley and Dr Ralph Vokes of Shimadzu Corp; and for plasma optical spectrophotometry analysis, Dr Thomas Schűtte of PLASUS GmbH. This work is supported by National Key Basic Research Program 973(2010CB327705), National Natural Science Foundation Project (51120125001, 51002031, 61101023, 51202028), Foundation of Doctoral Program of Ministry of Education (20100092110015), an EPSRC Impact Acceleration grant, and the Research Fund for International Young Scientists from NSFC (510501101 42, 51350110232). MT Cole thanks the Oppenheimer Trust for their generous financial support.This is the author accepted manuscript. The final version is available from the Royal Society of Chemistry via http://dx.doi.org/10.1039/C5RA20771